An analysis of the production and use of mullite-silica glass fiber refractories and prospects of increasing the production of them in Northern Dolomite Combine

Abstract

Types MKRR-130, MKRV-200, MKRP-340, MKRF-100, MKRPG, and MKRV-340 fiber materials to GOST 23619-79 are produced by Northern Dolomite Combine, Sukhoi Log Refractory Material Plant, and Pervoural'sk Dinas Plant. Individual experimental production lots of similar materials are produced to specification.According to an estimate made by the Ukrainian S cientific-Research Institute for Refractories, 43.5 % of all production is due to the share of steel industry plants using fiber materials, 18 % to assembly and construction administrations for the repair of heating equipment, 6.5 % to the energy and electrical industry, 5.9 % to the construction material industry, 3.4 % to chemistry and petrochemistry, 1.5% to the automobile industry, 2.4% to other machine building industries, and 1.2% is exported.Fiber materials are used most widely in the steel industi~ in blast furnace production for insulation of the walls and domes of hot blast stoves and the tops of blast furnaces, in compensation gaps, etc.In steel melting in teeming of certain types of steels inserts type MKRV-340 muUite-silica inserts are used for heating the top portion of the ingot, and MKRF-100 thin high-grade felt for sealing the joints between molds and hot tops (Taganrog Pipe Plant, Omutninsk Metallurgical Plant, Dnepr Special Steel).A promising direction is use of thermal insulation plates for the "cold lining" of continuous casting machine tundishes. This makes it possible to reduce the heat flow through the lining, increase its life, and eliminate preliminary heating of the ladle.Mechanized hoods are used for slow cooling of billets. The hoods are lined with MKRV-200 fiber. With a thickness of 60 mm cooling of billets from 770 to 200~ in 50 h is provided.Fiber refractories are widely used in roiling mill furnaces for insulating the vertical transverse and longitudinal hearth tubes of continuous furnaces and also in the thermal insulation layer of the linings of walls, hearths, and roofs of continuous furnaces and soaking pits.One of the rational places for use of fiber refractory materials is the lining of the walls and roofs of bell furnaces. According to the data of the State Union Institute for Design of Steel Casting and Rolling Production Equipment for Ferrous Metallurgy the use of fiber refractories makes it possible to: reduce the heat flow through the walls and roof, the shell temperature, and fuel consumption; reduce the heat content of the lining, which leads to an increase in productivity as the result of decreasing the time for heating and cooling; increase the size of the charge, which also increases productivity; reduce the labor requirement for installation of the lining as the result of use of mechanized methods. At present hundreds of bell furnaces with fiber linings are operating at Magnitogorsk and Krivoi Rog Metallurgical Combines and Novolipetsk, Chelyabinsk, Konstantinovka, and other plants.